package com.yuezhi.acl.security.filter;

import com.yuezhi.acl.security.handler.TokenManager;
import com.yuezhi.utils.R;
import com.yuezhi.utils.ResponseUtil;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.security.authentication.AuthenticationManager;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.SimpleGrantedAuthority;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.web.authentication.www.BasicAuthenticationFilter;
import org.springframework.util.StringUtils;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

/**
 * @program: security-demo
 * @description: 授权过滤器
 * @author: Mr.Liao
 * @create: 2020-12-06 15:17
 **/
public class TokenAuthFilter extends BasicAuthenticationFilter {

    private TokenManager tokenManager;
    private RedisTemplate redisTemplate;

    public TokenAuthFilter(AuthenticationManager authenticationManager, TokenManager tokenManager, RedisTemplate redisTemplate) {
        super(authenticationManager);
        this.tokenManager=tokenManager;
        this.redisTemplate=redisTemplate;
    }

    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain chain) throws IOException, ServletException {
        //获取当前认证成功用户权限信息
        UsernamePasswordAuthenticationToken authRequest = null;
        try {
            authRequest = getAuthentication(request);
        } catch (Exception e) {
            ResponseUtil.out(response, R.error());
        }
        //判断如果有权限信息，放到权限上下文中
        if(authRequest !=null){
            SecurityContextHolder.getContext().setAuthentication(authRequest);
        }else {
            ResponseUtil.out(response,R.error());
        }
        chain.doFilter(request,response);
    }

    private UsernamePasswordAuthenticationToken getAuthentication(HttpServletRequest request) {
        String token = request.getHeader("token");
        if (token != null && !"".equals(token.trim())) {
            //从token获取用户名
            String username = tokenManager.getUserInfoFromToken(token);
            //从redis获取对应权限列表
            List<String> permissionValueList = (List<String>)redisTemplate.opsForValue().get(username);
            Collection<GrantedAuthority> authority=new ArrayList<>();
            for (String permissionValue: permissionValueList ) {
                if(StringUtils.isEmpty(permissionValue)) continue;
                SimpleGrantedAuthority auth=new SimpleGrantedAuthority(permissionValue);
                authority.add(auth);
            }
            if(!StringUtils.isEmpty(username)){
                return new UsernamePasswordAuthenticationToken(username,token,authority);
            }
            return null;
        }
        return null;
    }
}
